[PATCH 3/5] rhashtable: Convert to nulls list

From: Thomas Graf
Date: Mon Sep 15 2014 - 08:19:29 EST

In order to allow wider usage of rhashtable, use a special nulls marker
to terminate each chain. The reason for not using the existing
nulls_list is that the pprev pointer usage would not be valid as entries
can be linked in two different buckets at the same time.

Signed-off-by: Thomas Graf <tgraf@xxxxxxx>
---
include/linux/list_nulls.h | 3 +-
include/linux/rhashtable.h | 195 +++++++++++++++++++++++++++++++--------------
lib/rhashtable.c | 158 ++++++++++++++++++++++--------------
net/netfilter/nft_hash.c | 12 ++-
net/netlink/af_netlink.c | 9 ++-
net/netlink/diag.c | 4 +-
6 files changed, 248 insertions(+), 133 deletions(-)

diff --git a/include/linux/list_nulls.h b/include/linux/list_nulls.h
index 5d10ae36..e8c300e 100644
--- a/include/linux/list_nulls.h
+++ b/include/linux/list_nulls.h
@@ -21,8 +21,9 @@ struct hlist_nulls_head {
struct hlist_nulls_node {
struct hlist_nulls_node *next, **pprev;
};
+#define NULLS_MARKER(value) (1UL | (((long)value) << 1))
#define INIT_HLIST_NULLS_HEAD(ptr, nulls) \
- ((ptr)->first = (struct hlist_nulls_node *) (1UL | (((long)nulls) << 1)))
+ ((ptr)->first = (struct hlist_nulls_node *) NULLS_MARKER(nulls))

#define hlist_nulls_entry(ptr, type, member) container_of(ptr,type,member)
/**
diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h
index 942fa44..e9cdbda 100644
--- a/include/linux/rhashtable.h
+++ b/include/linux/rhashtable.h
@@ -18,14 +18,12 @@
#ifndef _LINUX_RHASHTABLE_H
#define _LINUX_RHASHTABLE_H

-#include <linux/rculist.h>
+#include <linux/list_nulls.h>

struct rhash_head {
struct rhash_head __rcu *next;
};

-#define INIT_HASH_HEAD(ptr) ((ptr)->next = NULL)
-
struct bucket_table {
size_t size;
struct rhash_head __rcu *buckets[];
@@ -45,6 +43,7 @@ struct rhashtable;
* @hash_rnd: Seed to use while hashing
* @max_shift: Maximum number of shifts while expanding
* @min_shift: Minimum number of shifts while shrinking
+ * @nulls_base: Base value to generate nulls marker
* @hashfn: Function to hash key
* @obj_hashfn: Function to hash object
* @grow_decision: If defined, may return true if table should expand
@@ -59,6 +58,7 @@ struct rhashtable_params {
u32 hash_rnd;
size_t max_shift;
size_t min_shift;
+ int nulls_base;
rht_hashfn_t hashfn;
rht_obj_hashfn_t obj_hashfn;
bool (*grow_decision)(const struct rhashtable *ht,
@@ -82,6 +82,24 @@ struct rhashtable {
struct rhashtable_params p;
};

+static inline unsigned long rht_marker(const struct rhashtable *ht, u32 hash)
+{
+ return NULLS_MARKER(ht->p.nulls_base + hash);
+}
+
+#define INIT_RHT_NULLS_HEAD(ptr, ht, hash) \
+ ((ptr) = (typeof(ptr)) rht_marker(ht, hash))
+
+static inline bool rht_is_a_nulls(const struct rhash_head *ptr)
+{
+ return ((unsigned long) ptr & 1);
+}
+
+static inline unsigned long rht_get_nulls_value(const struct rhash_head *ptr)
+{
+ return ((unsigned long) ptr) >> 1;
+}
+
#ifdef CONFIG_PROVE_LOCKING
int lockdep_rht_mutex_is_held(const struct rhashtable *ht);
#else
@@ -119,92 +137,145 @@ void rhashtable_destroy(const struct rhashtable *ht);
#define rht_dereference_rcu(p, ht) \
rcu_dereference_check(p, lockdep_rht_mutex_is_held(ht))

-#define rht_entry(ptr, type, member) container_of(ptr, type, member)
-#define rht_entry_safe(ptr, type, member) \
-({ \
- typeof(ptr) __ptr = (ptr); \
- __ptr ? rht_entry(__ptr, type, member) : NULL; \
-})
+#define rht_dereference_bucket(p, tbl, hash) \
+ rcu_dereference_protected(p, lockdep_rht_mutex_is_held(ht))
+
+#define rht_dereference_bucket_rcu(p, tbl, hash) \
+ rcu_dereference_check(p, lockdep_rht_mutex_is_held(ht))
+
+#define rht_entry(tpos, pos, member) \
+ ({ tpos = container_of(pos, typeof(*tpos), member); 1; })

-#define rht_next_entry_safe(pos, ht, member) \
-({ \
- pos ? rht_entry_safe(rht_dereference((pos)->member.next, ht), \
- typeof(*(pos)), member) : NULL; \
-})
+static inline struct rhash_head *rht_get_bucket(const struct bucket_table *tbl,
+ u32 hash)
+{
+ return rht_dereference_bucket(tbl->buckets[hash], tbl, hash);
+}
+
+static inline struct rhash_head *rht_get_bucket_rcu(const struct bucket_table *tbl,
+ u32 hash)
+{
+ return rht_dereference_bucket_rcu(tbl->buckets[hash], tbl, hash);
+}
+
+/**
+ * rht_for_each_continue - continue iterating over hash chain
+ * @pos: the &struct rhash_head to use as a loop cursor.
+ * @head: the previous &struct rhash_head to continue from
+ * @tbl: the &struct bucket_table
+ * @hash: the hash value / bucket index
+ */
+#define rht_for_each_continue(pos, head, tbl, hash) \
+ for (pos = rht_dereference_bucket(head, tbl, hash); \
+ !rht_is_a_nulls(pos); \
+ pos = rht_dereference_bucket(pos->next, tbl, hash))

/**
* rht_for_each - iterate over hash chain
- * @pos: &struct rhash_head to use as a loop cursor.
- * @head: head of the hash chain (struct rhash_head *)
- * @ht: pointer to your struct rhashtable
+ * @pos: the &struct rhash_head to use as a loop cursor.
+ * @tbl: the &struct bucket_table
+ * @hash: the hash value / bucket index
*/
-#define rht_for_each(pos, head, ht) \
- for (pos = rht_dereference(head, ht); \
- pos; \
- pos = rht_dereference((pos)->next, ht))
+#define rht_for_each(pos, tbl, hash) \
+ for (pos = rht_get_bucket(tbl, hash); \
+ !rht_is_a_nulls(pos); \
+ pos = rht_dereference_bucket(pos->next, tbl, hash))

/**
* rht_for_each_entry - iterate over hash chain of given type
- * @pos: type * to use as a loop cursor.
- * @head: head of the hash chain (struct rhash_head *)
- * @ht: pointer to your struct rhashtable
- * @member: name of the rhash_head within the hashable struct.
+ * @tpos: the type * to use as a loop cursor.
+ * @pos: the &struct rhash_head to use as a loop cursor.
+ * @tbl: the &struct bucket_table
+ * @hash: the hash value / bucket index
+ * @member: name of the &struct rhash_head within the hashable struct.
*/
-#define rht_for_each_entry(pos, head, ht, member) \
- for (pos = rht_entry_safe(rht_dereference(head, ht), \
- typeof(*(pos)), member); \
- pos; \
- pos = rht_next_entry_safe(pos, ht, member))
+#define rht_for_each_entry(tpos, pos, tbl, hash, member) \
+ for (pos = rht_get_bucket(tbl, hash); \
+ (!rht_is_a_nulls(pos)) && rht_entry(tpos, pos, member); \
+ pos = rht_dereference_bucket(pos->next, tbl, hash))

/**
* rht_for_each_entry_safe - safely iterate over hash chain of given type
- * @pos: type * to use as a loop cursor.
- * @n: type * to use for temporary next object storage
- * @head: head of the hash chain (struct rhash_head *)
- * @ht: pointer to your struct rhashtable
- * @member: name of the rhash_head within the hashable struct.
+ * @tpos: the type * to use as a loop cursor.
+ * @pos: the &struct rhash_head to use as a loop cursor.
+ * @next: the &struct rhash_head to use as next in loop cursor.
+ * @tbl: the &struct bucket_table
+ * @hash: the hash value / bucket index
+ * @member: name of the &struct rhash_head within the hashable struct.
*
* This hash chain list-traversal primitive allows for the looped code to
* remove the loop cursor from the list.
*/
-#define rht_for_each_entry_safe(pos, n, head, ht, member) \
- for (pos = rht_entry_safe(rht_dereference(head, ht), \
- typeof(*(pos)), member), \
- n = rht_next_entry_safe(pos, ht, member); \
- pos; \
- pos = n, \
- n = rht_next_entry_safe(pos, ht, member))
+#define rht_for_each_entry_safe(tpos, pos, next, tbl, hash, member) \
+ for (pos = rht_get_bucket(tbl, hash), \
+ next = !rht_is_a_nulls(pos) ? \
+ rht_dereference_bucket(pos->next, tbl, hash) : \
+ (struct rhash_head *) NULLS_MARKER(0); \
+ (!rht_is_a_nulls(pos)) && rht_entry(tpos, pos, member); \
+ pos = next)
+
+/**
+ * rht_for_each_rcu_continue - continue iterating over rcu hash chain
+ * @pos: the &struct rhash_head to use as a loop cursor.
+ * @head: the previous &struct rhash_head to continue from
+ *
+ * This hash chain list-traversal primitive may safely run concurrently with
+ * the _rcu mutation primitives such as rht_insert() as long as the traversal
+ * is guarded by rcu_read_lock().
+ */
+#define rht_for_each_rcu_continue(pos, head) \
+ for (({barrier(); }), pos = rcu_dereference_raw(head); \
+ !rht_is_a_nulls(pos); \
+ pos = rcu_dereference_raw(pos->next))

/**
* rht_for_each_rcu - iterate over rcu hash chain
- * @pos: &struct rhash_head to use as a loop cursor.
- * @head: head of the hash chain (struct rhash_head *)
- * @ht: pointer to your struct rhashtable
+ * @pos: the &struct rhash_head to use as a loop cursor.
+ * @tbl: the &struct bucket_table
+ * @hash: the hash value / bucket index
+ *
+ * This hash chain list-traversal primitive may safely run concurrently with
+ * the _rcu mutation primitives such as rht_insert() as long as the traversal
+ * is guarded by rcu_read_lock().
+ */
+#define rht_for_each_rcu(pos, tbl, hash) \
+ for (({barrier(); }), pos = rht_get_bucket_rcu(tbl, hash); \
+ !rht_is_a_nulls(pos); \
+ pos = rcu_dereference_raw(pos->next))
+
+/**
+ * rht_for_each_entry_rcu_continue - continue iterating over rcu hash chain
+ * @tpos: the type * to use as a loop cursor.
+ * @pos: the &struct rhash_head to use as a loop cursor.
+ * @head: the previous &struct rhash_head to continue from
+ * @member: name of the &struct rhash_head within the hashable struct.
*
* This hash chain list-traversal primitive may safely run concurrently with
- * the _rcu fkht mutation primitives such as rht_insert() as long as the
- * traversal is guarded by rcu_read_lock().
+ * the _rcu mutation primitives such as rht_insert() as long as the traversal
+ * is guarded by rcu_read_lock().
*/
-#define rht_for_each_rcu(pos, head, ht) \
- for (pos = rht_dereference_rcu(head, ht); \
- pos; \
- pos = rht_dereference_rcu((pos)->next, ht))
+#define rht_for_each_entry_rcu_continue(tpos, pos, head, member) \
+ for (({barrier(); }), \
+ pos = rcu_dereference_raw(head); \
+ (!rht_is_a_nulls(pos)) && rht_entry(tpos, pos, member); \
+ pos = rcu_dereference_raw(pos->next))

/**
* rht_for_each_entry_rcu - iterate over rcu hash chain of given type
- * @pos: type * to use as a loop cursor.
- * @head: head of the hash chain (struct rhash_head *)
- * @member: name of the rhash_head within the hashable struct.
+ * @tpos: the type * to use as a loop cursor.
+ * @pos: the &struct rhash_head to use as a loop cursor.
+ * @tbl: the &struct bucket_table
+ * @hash: the hash value / bucket index
+ * @member: name of the &struct rhash_head within the hashable struct.
*
* This hash chain list-traversal primitive may safely run concurrently with
- * the _rcu fkht mutation primitives such as rht_insert() as long as the
- * traversal is guarded by rcu_read_lock().
+ * the _rcu mutation primitives such as rht_insert() as long as the traversal
+ * is guarded by rcu_read_lock().
*/
-#define rht_for_each_entry_rcu(pos, head, member) \
- for (pos = rht_entry_safe(rcu_dereference_raw(head), \
- typeof(*(pos)), member); \
- pos; \
- pos = rht_entry_safe(rcu_dereference_raw((pos)->member.next), \
- typeof(*(pos)), member))
+#define rht_for_each_entry_rcu(tpos, pos, tbl, hash, member) \
+ for (({barrier(); }), \
+ pos = rht_get_bucket_rcu(tbl, hash); \
+ (!rht_is_a_nulls(pos)) && rht_entry(tpos, pos, member); \
+ pos = rht_dereference_bucket_rcu(pos->next, tbl, hash))

#endif /* _LINUX_RHASHTABLE_H */
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index c10df45..d871483 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -28,6 +28,23 @@
#define HASH_DEFAULT_SIZE 64UL
#define HASH_MIN_SIZE 4UL

+/*
+ * The nulls marker consists of:
+ *
+ * +-------+-----------------------------------------------------+-+
+ * | Base | Hash |1|
+ * +-------+-----------------------------------------------------+-+
+ *
+ * Base (4 bits) : Reserved to distinguish between multiple tables.
+ * Specified via &struct rhashtable_params.nulls_base.
+ * Hash (27 bits): Full hash (unmasked) of first element added to bucket
+ * 1 (1 bit) : Nulls marker (always set)
+ *
+ */
+#define HASH_BASE_BITS 4
+#define HASH_BASE_MIN (1 << (31 - HASH_BASE_BITS))
+#define HASH_RESERVED_SPACE (HASH_BASE_BITS + 1)
+
#define ASSERT_RHT_MUTEX(HT) BUG_ON(!lockdep_rht_mutex_is_held(HT))

#ifdef CONFIG_PROVE_LOCKING
@@ -43,14 +60,22 @@ static void *rht_obj(const struct rhashtable *ht, const struct rhash_head *he)
return (void *) he - ht->p.head_offset;
}

-static u32 __hashfn(const struct rhashtable *ht, const void *key,
- u32 len, u32 hsize)
+static u32 rht_bucket_index(u32 hash, const struct bucket_table *tbl)
{
- u32 h;
+ return hash & (tbl->size - 1);
+}

- h = ht->p.hashfn(key, len, ht->p.hash_rnd);
+static u32 obj_raw_hashfn(const struct rhashtable *ht, const void *ptr)
+{
+ u32 hash;
+
+ if (unlikely(!ht->p.key_len))
+ hash = ht->p.obj_hashfn(ptr, ht->p.hash_rnd);
+ else
+ hash = ht->p.hashfn(ptr + ht->p.key_offset, ht->p.key_len,
+ ht->p.hash_rnd);

- return h & (hsize - 1);
+ return hash >> HASH_RESERVED_SPACE;
}

/**
@@ -66,23 +91,14 @@ static u32 __hashfn(const struct rhashtable *ht, const void *key,
u32 rhashtable_hashfn(const struct rhashtable *ht, const void *key, u32 len)
{
struct bucket_table *tbl = rht_dereference_rcu(ht->tbl, ht);
+ u32 hash;

- return __hashfn(ht, key, len, tbl->size);
-}
-EXPORT_SYMBOL_GPL(rhashtable_hashfn);
-
-static u32 obj_hashfn(const struct rhashtable *ht, const void *ptr, u32 hsize)
-{
- if (unlikely(!ht->p.key_len)) {
- u32 h;
-
- h = ht->p.obj_hashfn(ptr, ht->p.hash_rnd);
-
- return h & (hsize - 1);
- }
+ hash = ht->p.hashfn(key, len, ht->p.hash_rnd);
+ hash >>= HASH_RESERVED_SPACE;

- return __hashfn(ht, ptr + ht->p.key_offset, ht->p.key_len, hsize);
+ return rht_bucket_index(hash, tbl);
}
+EXPORT_SYMBOL_GPL(rhashtable_hashfn);

/**
* rhashtable_obj_hashfn - compute hash for hashed object
@@ -98,20 +114,23 @@ u32 rhashtable_obj_hashfn(const struct rhashtable *ht, void *ptr)
{
struct bucket_table *tbl = rht_dereference_rcu(ht->tbl, ht);

- return obj_hashfn(ht, ptr, tbl->size);
+ return rht_bucket_index(obj_raw_hashfn(ht, ptr), tbl);
}
EXPORT_SYMBOL_GPL(rhashtable_obj_hashfn);

static u32 head_hashfn(const struct rhashtable *ht,
- const struct rhash_head *he, u32 hsize)
+ const struct rhash_head *he,
+ const struct bucket_table *tbl)
{
- return obj_hashfn(ht, rht_obj(ht, he), hsize);
+ return rht_bucket_index(obj_raw_hashfn(ht, rht_obj(ht, he)), tbl);
}

-static struct bucket_table *bucket_table_alloc(size_t nbuckets)
+static struct bucket_table *bucket_table_alloc(struct rhashtable *ht,
+ size_t nbuckets)
{
struct bucket_table *tbl;
size_t size;
+ int i;

size = sizeof(*tbl) + nbuckets * sizeof(tbl->buckets[0]);
tbl = kzalloc(size, GFP_KERNEL);
@@ -121,6 +140,9 @@ static struct bucket_table *bucket_table_alloc(size_t nbuckets)
if (tbl == NULL)
return NULL;

+ for (i = 0; i < nbuckets; i++)
+ INIT_RHT_NULLS_HEAD(tbl->buckets[i], ht, i);
+
tbl->size = nbuckets;

return tbl;
@@ -159,34 +181,36 @@ static void hashtable_chain_unzip(const struct rhashtable *ht,
const struct bucket_table *new_tbl,
struct bucket_table *old_tbl, size_t n)
{
- struct rhash_head *he, *p, *next;
- unsigned int h;
+ struct rhash_head *he, *p;
+ struct rhash_head __rcu *next;
+ u32 hash, new_tbl_idx;

/* Old bucket empty, no work needed. */
- p = rht_dereference(old_tbl->buckets[n], ht);
- if (!p)
+ p = rht_get_bucket(old_tbl, n);
+ if (rht_is_a_nulls(p))
return;

/* Advance the old bucket pointer one or more times until it
* reaches a node that doesn't hash to the same bucket as the
* previous node p. Call the previous node p;
*/
- h = head_hashfn(ht, p, new_tbl->size);
- rht_for_each(he, p->next, ht) {
- if (head_hashfn(ht, he, new_tbl->size) != h)
+ hash = obj_raw_hashfn(ht, rht_obj(ht, p));
+ new_tbl_idx = rht_bucket_index(hash, new_tbl);
+ rht_for_each_continue(he, p->next, old_tbl, n) {
+ if (head_hashfn(ht, he, new_tbl) != new_tbl_idx)
break;
p = he;
}
- RCU_INIT_POINTER(old_tbl->buckets[n], p->next);
+ RCU_INIT_POINTER(old_tbl->buckets[n], he);

/* Find the subsequent node which does hash to the same
* bucket as node P, or NULL if no such node exists.
*/
- next = NULL;
- if (he) {
- rht_for_each(he, he->next, ht) {
- if (head_hashfn(ht, he, new_tbl->size) == h) {
- next = he;
+ INIT_RHT_NULLS_HEAD(next, ht, hash);
+ if (!rht_is_a_nulls(he)) {
+ rht_for_each_continue(he, he->next, old_tbl, n) {
+ if (head_hashfn(ht, he, new_tbl) == new_tbl_idx) {
+ next = (struct rhash_head __rcu *) he;
break;
}
}
@@ -223,7 +247,7 @@ int rhashtable_expand(struct rhashtable *ht)
if (ht->p.max_shift && ht->shift >= ht->p.max_shift)
return 0;

- new_tbl = bucket_table_alloc(old_tbl->size * 2);
+ new_tbl = bucket_table_alloc(ht, old_tbl->size * 2);
if (new_tbl == NULL)
return -ENOMEM;

@@ -239,8 +263,8 @@ int rhashtable_expand(struct rhashtable *ht)
*/
for (i = 0; i < new_tbl->size; i++) {
h = i & (old_tbl->size - 1);
- rht_for_each(he, old_tbl->buckets[h], ht) {
- if (head_hashfn(ht, he, new_tbl->size) == i) {
+ rht_for_each(he, old_tbl, h) {
+ if (head_hashfn(ht, he, new_tbl) == i) {
RCU_INIT_POINTER(new_tbl->buckets[i], he);
break;
}
@@ -268,7 +292,7 @@ int rhashtable_expand(struct rhashtable *ht)
complete = true;
for (i = 0; i < old_tbl->size; i++) {
hashtable_chain_unzip(ht, new_tbl, old_tbl, i);
- if (old_tbl->buckets[i] != NULL)
+ if (!rht_is_a_nulls(old_tbl->buckets[i]))
complete = false;
}
} while (!complete);
@@ -299,7 +323,7 @@ int rhashtable_shrink(struct rhashtable *ht)
if (ht->shift <= ht->p.min_shift)
return 0;

- ntbl = bucket_table_alloc(tbl->size / 2);
+ ntbl = bucket_table_alloc(ht, tbl->size / 2);
if (ntbl == NULL)
return -ENOMEM;

@@ -316,8 +340,9 @@ int rhashtable_shrink(struct rhashtable *ht)
* in the old table that contains entries which will hash
* to the new bucket.
*/
- for (pprev = &ntbl->buckets[i]; *pprev != NULL;
- pprev = &rht_dereference(*pprev, ht)->next)
+ for (pprev = &ntbl->buckets[i];
+ !rht_is_a_nulls(rht_dereference_bucket(*pprev, ntbl, i));
+ pprev = &rht_dereference_bucket(*pprev, ntbl, i)->next)
;
RCU_INIT_POINTER(*pprev, tbl->buckets[i + ntbl->size]);
}
@@ -350,13 +375,17 @@ EXPORT_SYMBOL_GPL(rhashtable_shrink);
void rhashtable_insert(struct rhashtable *ht, struct rhash_head *obj)
{
struct bucket_table *tbl = rht_dereference(ht->tbl, ht);
- u32 hash;
+ u32 hash, idx;

ASSERT_RHT_MUTEX(ht);

- hash = head_hashfn(ht, obj, tbl->size);
- RCU_INIT_POINTER(obj->next, tbl->buckets[hash]);
- rcu_assign_pointer(tbl->buckets[hash], obj);
+ hash = obj_raw_hashfn(ht, rht_obj(ht, obj));
+ idx = rht_bucket_index(hash, tbl);
+ if (rht_is_a_nulls(rht_get_bucket(tbl, idx)))
+ INIT_RHT_NULLS_HEAD(obj->next, ht, hash);
+ else
+ obj->next = tbl->buckets[idx];
+ rcu_assign_pointer(tbl->buckets[idx], obj);
ht->nelems++;

if (ht->p.grow_decision && ht->p.grow_decision(ht, tbl->size))
@@ -410,14 +439,13 @@ bool rhashtable_remove(struct rhashtable *ht, struct rhash_head *obj)
struct bucket_table *tbl = rht_dereference(ht->tbl, ht);
struct rhash_head __rcu **pprev;
struct rhash_head *he;
- u32 h;
+ u32 idx;

ASSERT_RHT_MUTEX(ht);

- h = head_hashfn(ht, obj, tbl->size);
-
- pprev = &tbl->buckets[h];
- rht_for_each(he, tbl->buckets[h], ht) {
+ idx = head_hashfn(ht, obj, tbl);
+ pprev = &tbl->buckets[idx];
+ rht_for_each(he, tbl, idx) {
if (he != obj) {
pprev = &he->next;
continue;
@@ -453,12 +481,12 @@ void *rhashtable_lookup(const struct rhashtable *ht, const void *key)

BUG_ON(!ht->p.key_len);

- h = __hashfn(ht, key, ht->p.key_len, tbl->size);
- rht_for_each_rcu(he, tbl->buckets[h], ht) {
+ h = rhashtable_hashfn(ht, key, ht->p.key_len);
+ rht_for_each_rcu(he, tbl, h) {
if (memcmp(rht_obj(ht, he) + ht->p.key_offset, key,
ht->p.key_len))
continue;
- return (void *) he - ht->p.head_offset;
+ return rht_obj(ht, he);
}

return NULL;
@@ -489,7 +517,7 @@ void *rhashtable_lookup_compare(const struct rhashtable *ht, u32 hash,
if (unlikely(hash >= tbl->size))
return NULL;

- rht_for_each_rcu(he, tbl->buckets[hash], ht) {
+ rht_for_each_rcu(he, tbl, hash) {
if (!compare(rht_obj(ht, he), arg))
continue;
return (void *) he - ht->p.head_offset;
@@ -560,19 +588,23 @@ int rhashtable_init(struct rhashtable *ht, struct rhashtable_params *params)
(!params->key_len && !params->obj_hashfn))
return -EINVAL;

+ if (params->nulls_base && params->nulls_base < HASH_BASE_MIN)
+ return -EINVAL;
+
params->min_shift = max_t(size_t, params->min_shift,
ilog2(HASH_MIN_SIZE));

if (params->nelem_hint)
size = rounded_hashtable_size(params);

- tbl = bucket_table_alloc(size);
+ memset(ht, 0, sizeof(*ht));
+ memcpy(&ht->p, params, sizeof(*params));
+
+ tbl = bucket_table_alloc(ht, size);
if (tbl == NULL)
return -ENOMEM;

- memset(ht, 0, sizeof(*ht));
ht->shift = ilog2(tbl->size);
- memcpy(&ht->p, params, sizeof(*params));
RCU_INIT_POINTER(ht->tbl, tbl);

if (!ht->p.hash_rnd)
@@ -652,6 +684,7 @@ static void test_bucket_stats(struct rhashtable *ht, struct bucket_table *tbl,
bool quiet)
{
unsigned int cnt, rcu_cnt, i, total = 0;
+ struct rhash_head *pos;
struct test_obj *obj;

for (i = 0; i < tbl->size; i++) {
@@ -660,7 +693,7 @@ static void test_bucket_stats(struct rhashtable *ht, struct bucket_table *tbl,
if (!quiet)
pr_info(" [%#4x/%zu]", i, tbl->size);

- rht_for_each_entry_rcu(obj, tbl->buckets[i], node) {
+ rht_for_each_entry_rcu(obj, pos, tbl, i, node) {
cnt++;
total++;
if (!quiet)
@@ -689,7 +722,8 @@ static void test_bucket_stats(struct rhashtable *ht, struct bucket_table *tbl,
static int __init test_rhashtable(struct rhashtable *ht)
{
struct bucket_table *tbl;
- struct test_obj *obj, *next;
+ struct test_obj *obj;
+ struct rhash_head *pos, *next;
int err;
unsigned int i;

@@ -755,7 +789,7 @@ static int __init test_rhashtable(struct rhashtable *ht)
error:
tbl = rht_dereference_rcu(ht->tbl, ht);
for (i = 0; i < tbl->size; i++)
- rht_for_each_entry_safe(obj, next, tbl->buckets[i], ht, node)
+ rht_for_each_entry_safe(obj, pos, next, tbl, i, node)
kfree(obj);

return err;
diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c
index b52873c..68b654b 100644
--- a/net/netfilter/nft_hash.c
+++ b/net/netfilter/nft_hash.c
@@ -99,12 +99,13 @@ static int nft_hash_get(const struct nft_set *set, struct nft_set_elem *elem)
const struct rhashtable *priv = nft_set_priv(set);
const struct bucket_table *tbl = rht_dereference_rcu(priv->tbl, priv);
struct rhash_head __rcu * const *pprev;
+ struct rhash_head *pos;
struct nft_hash_elem *he;
u32 h;

h = rhashtable_hashfn(priv, &elem->key, set->klen);
pprev = &tbl->buckets[h];
- rht_for_each_entry_rcu(he, tbl->buckets[h], node) {
+ rht_for_each_entry_rcu(he, pos, tbl, h, node) {
if (nft_data_cmp(&he->key, &elem->key, set->klen)) {
pprev = &he->node.next;
continue;
@@ -130,7 +131,9 @@ static void nft_hash_walk(const struct nft_ctx *ctx, const struct nft_set *set,

tbl = rht_dereference_rcu(priv->tbl, priv);
for (i = 0; i < tbl->size; i++) {
- rht_for_each_entry_rcu(he, tbl->buckets[i], node) {
+ struct rhash_head *pos;
+
+ rht_for_each_entry_rcu(he, pos, tbl, i, node) {
if (iter->count < iter->skip)
goto cont;

@@ -181,12 +184,13 @@ static void nft_hash_destroy(const struct nft_set *set)
{
const struct rhashtable *priv = nft_set_priv(set);
const struct bucket_table *tbl;
- struct nft_hash_elem *he, *next;
+ struct nft_hash_elem *he;
+ struct rhash_head *pos, *next;
unsigned int i;

tbl = rht_dereference(priv->tbl, priv);
for (i = 0; i < tbl->size; i++)
- rht_for_each_entry_safe(he, next, tbl->buckets[i], priv, node)
+ rht_for_each_entry_safe(he, pos, next, tbl, i, node)
nft_hash_elem_destroy(set, he);

rhashtable_destroy(priv);
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index a1e6104..98e5b58 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2903,7 +2903,9 @@ static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos)
const struct bucket_table *tbl = rht_dereference_rcu(ht->tbl, ht);

for (j = 0; j < tbl->size; j++) {
- rht_for_each_entry_rcu(nlk, tbl->buckets[j], node) {
+ struct rhash_head *node;
+
+ rht_for_each_entry_rcu(nlk, node, tbl, j, node) {
s = (struct sock *)nlk;

if (sock_net(s) != seq_file_net(seq))
@@ -2929,6 +2931,7 @@ static void *netlink_seq_start(struct seq_file *seq, loff_t *pos)

static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
+ struct rhash_head *node;
struct netlink_sock *nlk;
struct nl_seq_iter *iter;
struct net *net;
@@ -2943,7 +2946,7 @@ static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
iter = seq->private;
nlk = v;

- rht_for_each_entry_rcu(nlk, nlk->node.next, node)
+ rht_for_each_entry_rcu_continue(nlk, node, nlk->node.next, node)
if (net_eq(sock_net((struct sock *)nlk), net))
return nlk;

@@ -2955,7 +2958,7 @@ static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
const struct bucket_table *tbl = rht_dereference_rcu(ht->tbl, ht);

for (; j < tbl->size; j++) {
- rht_for_each_entry_rcu(nlk, tbl->buckets[j], node) {
+ rht_for_each_entry_rcu(nlk, node, tbl, j, node) {
if (net_eq(sock_net((struct sock *)nlk), net)) {
iter->link = i;
iter->hash_idx = j;
diff --git a/net/netlink/diag.c b/net/netlink/diag.c
index de8c74a..1062bb4 100644
--- a/net/netlink/diag.c
+++ b/net/netlink/diag.c
@@ -113,7 +113,9 @@ static int __netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
req = nlmsg_data(cb->nlh);

for (i = 0; i < htbl->size; i++) {
- rht_for_each_entry(nlsk, htbl->buckets[i], ht, node) {
+ struct rhash_head *node;
+
+ rht_for_each_entry(nlsk, node, htbl, i, node) {
sk = (struct sock *)nlsk;

if (!net_eq(sock_net(sk), net))
--
1.9.3

--
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